The present invention relates to recycling and reclaiming waste polymeric material, and forming an article therefrom, and more particularly forming a floor covering utilizing the recycled and reclaimed waste polymeric material.
There has been an increased interest in recycling, reclaiming and reutilizing waste and scrap material, and particularly waste thermoplastic polymeric material from a variety of sources. The recycling of most mixtures of thermoplastic scrap material is limited by the incompatibility of the various different kinds of thermoplastic material present in the scrap. For example, the various thermoplastic resins are often insoluble in each other resulting in a heterogeneous mixture in which each type of resin forms a dispersed phase in the other. This often adversely affects the mechanical properties (e.g. tensile and impact strength) and aesthetic properties of any articles formed from such a mixture.
One suggestion to overcome this problem is to sort the scrap material based on the specific thermoplastic material present. Such sorting, however, is often impractical from both a technical and economic standpoint. Thus, various other solutions have been proposed with respect to recycling waste polymeric material. For example, U.S. Pat. No. 4,250,222 to Mavel et al. proposes coarsely grinding a mixture of two or more mutually incompatible thermoplastic resins, incorporating into the coarsely ground thermoplastic resin mixture, through the application of heat and pressure, from about 5 to about 25 parts of weight of a fibrous material, and forming the resin/fiber mass into an article.
U.S. Pat. No. 4,968,462 to Levasseur proposes shredding or granulating polymeric waste, drying the material to a water content of not more than 8% by weight, preheating the material to a temperature of 80.degree. C. to 160.degree. C., kneading at a temperature of 120.degree. C. to 250.degree. C. and injection molding or extruding the material to form a product such as a fence post.
Processes for recycling floor covering have also been desired inasmuch as a particularly large amount of scrap material is generated during the manufacture of floor covering. For example, in the manufacture of tufted carpet, the tufted carpet may have nylon pile secured in a primary backing of a woven polypropylene fabric which has a secondary vinyl plastic backing. The pile, the primary backing and secondary backing are typically each a thermoplastic having different characteristics.
Specific to recycling carpet, U.S. Pat. No. 4,028,159 to Norris proposes a process for reclaiming selvedge formed during manufacturing. The process comprises heating the selvedge in air to a temperature above the melting points of the resins to melt and degrade the resins; separating melted resin from solid residue to reclaim meltable resin from the selvedge; and utilizing the reclaimed resins as a substitute for at least a portion of the high molecular weight resins in an adhesive mixture in subsequent carpet production.
U.S. Pat. No. 4,158,645 to Benkowski et al. proposes applying a shearing force (e.g., using a Banbury mixer) to tear the fabric fibers into lengths no greater than about 0.25 inch. This forms a mixture of thermoplastic-resin and short lengths of fabric fibers. The resulting mixture is subjected to heat and pressure, such as by a drop mill and thus banded. After the mixture is banded, it can be calendared onto a web of fabric to form a finished reinforced sheet or extruded into various continuous forms such as sheets or strips. The process is described as being particularly useful as applied to scrap polyvinyl chloride sheet material reinforced with cotton fabric.
These processes of recycling or reclaiming scrap material, however, are not entirely successful and have not found widespread usage because of economic infeasibility and limitations on the types of article which can be made. Thus, it is among the objects of the invention to provide an improved process of recycling, reclaiming, and reutilizing scrap material, and particularly thermoplastic scrap material from the manufacture of floor covering or the subsequent removal of the floor covering after installation.
It is another object of the present invention to provide a new floor covering using the recycled and reclaimed scrap material.